Push rod mechanism



March 7, 1961 J. H. WILLIAMS 2,973,663

`PUSH Ron MECHANISM Filed Jan. 2, 1959 2 Sheets-Sheet 1 Marh 7, 1961 J. H. WILLIAMS 2,973,663

PUSH ROD MECHANISM Filed Jan. 2, 1959 2 Sheets-Sheet 2 m5 j@ if Pusnnon MECHANISM John H. Williams, Barrington, Ill., assignor to Oak y#lVIauutacturing C0., a corporation of Deiaware Fileshare, 1959, ser. 10,784,569

3 Claims. (cuit-483) This invention relates to a push rod mechanism and more particularly to a push rod mechanism wherein `a novel push rod release means yis provided.

Push rod mechanisms for use in connection with electric switches and the like are well known. As an example, a push rod mechanism to which the present invention may be readily applied is disclosed in United States Patent No. 2,213,845 issued on September 3, 1940. In the mechanism described therein,-a number of push rods are arranged in laterally offset spaced parallel relation. A latch bar is provided for locking a push rod to an in position and releasing a previously locked different pushrod. It is sometimes Vdesirable to provide a special push rod for releasing any one or more locked push rods `andcapable of being released itself by operation of this same push rod. In the push rod mechanism illustrated inthe patent, a locked push rod can only be released by operation of a dilerent push rod.

This invention provides means whereby a 'push rod may be operatednot only to release other push-rodsfrorn a locked position but also to release itself without reliance on any other push rod.

For an understanding of the invention, `reference will be made to the drawing wherein Figure l is a side View with certain parts broken away of a `push rod mechanism embodying the present invention.

" for the other push rods.

Figure 2 isV a detail of the mechanism villustrated in Y Figure 5 is a detail illustrating the new release mechanism in one position. y j n Figure 6 is a detail showing the new release mechanism in a different position.

The push button mechanism 1 generally includes front i or-top support strip 10 having anges 11`bent down along 'eachside thereof. Spaced from and parallel to strip 1t) f is bottom or rear `support ystripV 12 of generally similar construction. `End members I4 and 15 extend between the top and bottom strips and are rigidly attached thereto to' provide a rigid structure. -End members 14and 15 support insulating sh'eet 17 carrying a number of electrical contacts. Insulating sheet 17 also supports a `nurn- Aber of movable insulating strips, .such as 19, carrying movable contacts. Slidably mounted in plates 10 and 12 are a `number of push rods 21 to 23 inclusive. Three push'rods are here illustrated for convenience but'as is well known, as many push rods may be provided as are necessary. The push rods are disposed in laterally offset spaced parallel relation.

Referring specifically to push rod 21, this has rodfportions 25 and 26 at the top and bottom portions `of the vrod and between these rod portions there is body portion 27. Rod portion 25 operates in a slot in plate 10 while rod portion 26 operates in a slot in plate 12. The

35 for cooperation withthe push rod;

In order to lock push rod 21 to an in position, body 27 onthe push rod is provided with locking slot 36 disposed above, as vseen in Figures l and 2, latch bar slot 33. Latch bar 34 is biased toward the left as seen in Figures l and 2by coil spring 38 disposed around a p0rltion of the latch bar projecting beyond end plate 14.

"Coil spring 38 is kept in position by head 39 ofthe latch bar.

The structure so far described is generally conventional and is disclosed for example, in the patent above identified. In this particular construction, if push rod 21 ismoved down, it will release other push rods and at the same time will itself stay locked in adown position. In order to release pushrod 21, push rod 22 can be moved downwardly whereupon rod 22 will be locked in aV down position.

Push rod 23 is provided with suitable means to be described whereby push rod 23 may be moved downwardly once to release any other push rod, such as 21 or 22 for example, and lock push rod 23 to an in position. A second inward movement of push rod 23 will ,function to release push rod 23 to an out position;

Referring now to push rod V23, body 27a thereof is provided lwith `slot 40 for accommodating the latch b'ar.v

Latch bar 34 does not have any tooth similar to tooth 35 Body 27a near top plate 10 is provided with'pivot pin 41 upon whichis disposed rocker arm 42 having 4slot 43 through which pin 41 passes. Slot 43 has the shape of an L so that rocker arm d2 may not only pivot with respect to pin 41 but may also move transversely of the pin. Washer 45 carried by the end of pin 41 locks rocker arm 42 on the pin. Rocker arm 42 has a cam surface 46 against which spring arm 47 presses. Spring arm 47 extends toward the bottom of body portion y27a and around rod portion 28a to -be locked to the Vpush rod.

VRocker arm' 42 also has cam portion 511 which is adapted to cooperate with cam Vplate 51 rigidly supported from` plate 10j 'Latch bar 34 has pivotally supported 4thereon at53 dog 54. Dog 54 has one end 55 apertured for accommodating the end of bias spring 56, the other end of the bias spring being secured to a part of the latch bar. Bias spring 56 tends to pull dog portion 55 up as seen in Figures l, 2, 5 and 6. Dog 5dV has tooth 58 provided with edges 59 and 6i?. Edges 59 and 60 are at an angle to each other Vand meet at the very'tip of tooth 58. Tooth 58 is rockable over a limited range, this being determined by bent'portion 61 of dog 54 operating between edge portions `62 and 63 of the latch bar. Cooperating with edge portion 59 of ldog 54 is finger 65 bent from the push rod material toward the dog.

As dog 54 is biased to its normal position as illustrated inFigures l, 2, 5 and 6, finger 65 of the body of pu'sh rod 23 will tend to be forced againstedge 59 of the dog when push rod 23 is moved downwardly. Thus, when push rod 23 is moved from a normal out position, as `seen in Figures l and 2, for example, downwardly, ldog y'54 will be engaged by finger -65 of the push rod to `r'nove the latch bar to the right, as seen `in Figures 1 and 2; The movement of the latch bar to the `right will release lany other push rod which happens to be down, such as,

VPatented Mar. 7, 1951 y for example, push rod 22 in Figure 2. Once iinger 65 is past the tip of dog 54, the latch bar can return to normal position. lf no means are provided for retaining push rod V23 to an in position, it is clear that push rod 23 will return to its topposition, as seen in Figure 1, since linger 65 on the way up can pass tip 58 of the dog. However, rocker 42 is adapted to retain the push rod in a down position, not necessarily the furthest position down, by means provided therefor.

Referring specifically to Figure 4, .rocker 42 has bottom portion y67 provided with shoulders 68. Shoulder 68 upon downward movement of rocker y42 with push rod 23 will slide along the surface of the latchbar until edge 70 is reached, permitting rocker 42 to turn clockwise, as seen in Figure 4, so that shoulder 68 can engage bottom edge 70 of the latch bar.V This rocking will be due to a combination of actions by spring 47 and cam plate S1. L-shaped slot 43 aids in permitting rocker 42 to move to a locking position. When push rod 23 is moved downwardly from its locked position, this downward movement being enough to cause spring 47 to ride on cam surface 46 of rocker 42 and force the rocker to the left, as seen in Figure 4. This leftward movement of the rocker with reference to pin 41 is permissible due to shape of slot 43. This general rocker construction and push-push action is more fully disclosed and claimed in my previous United States Patent No. 2,857,781, issued October 28, 1958. In the present application, this push-push action is combined with latch bar operating means shown in detail in Figure 6 for providing a novel combination. Instead of the push-push latching means disclosed here and in the patent referred to above, any other push-push latching means may be used.

In general, any suitable latch bar mechanism for cooperating with push rods may be used where the locking and unlocking of a push rod is controlled by the longitudinal movement of a latch bar. Added to such a construction is at least one additional push rod having the special push-push action described.

Instead of having a pivoted dog on the latch bar, it is possible to use any other detent means for providing engagement between the latch bar and additional push sists of an additional push rod movable longitudinally between an out and in position, means interconnecting said additional push rod and said latch bar for moving said latch bar to a push rod unlocking position upon movement of said additional push rod from an out to an in position, said interconnecting means permitting said additional push rod to move from an in position to an out position without affecting said latch bar and means cooperating with said additional push rod for locking said additional push rod to an in position after it is moved from an out to an innermost position, and for unlocking said additional push rod when said additional push rod is again moved from its locked in posito its innermost position, rsaid interconnecting means comprising a pivoted dog having a tooth portion for cooperation with said additional push rod, said dog being movable to clear said push rod upon outward movement thereof and to engage upon inward movement of -said additional push rod.

2. The construction according to claim 1 wherein said means for locking said additional push rod to an in position includes a rocker mounted for limited rocking and translational movement with respect to said additional push rod, said rocker having a shouldered portion for engaging said latch bar, said rocker having spring means and cam surfaces cooperating therewith to move said rocker respectively to a locking or unlocking position after successive movements inwardly of said additional push rod.

3. In a multi-push rod mechanism, the combination of a plurality of spaced, laterally offset, longitudinally movable push rods, means for biasing said push rods to a normal out position from which position said push rods are manually operable to an in position, latch bar means disposed transversely of said push rods, said latch bar means providing a tooth on said latch bar for cooperation with a push rod, each push rod having its rod upon inward movement of said additional push rod from an out position while permitting said additional push rod to move freely insofar as the latch bar is concerned in an outward direction.

As is clearly evident, the additional push rod 'here is normally biased to an out position and is movable manually from said out position toward an innermost position. The normal in position of the `additional push rod is between the out position of the additional push rod and the innermost position thereof. A push-push mechanism clearly requires a stable in position between a stable out position and some innermost position. Obviously the innermost position of the adlitional push rod is not a stable position. Hence, the one way means for coupling the additional push rod to the latch bar should only act when the additional push rod moves from its out position to its in position.

The additional push rod must continue beyond the in position to some innermost position and then returns to a stable in position. From this stable in position the additional push rod is again movable inwardly for a distance after which it is free to return to its normal out position in response to its bias.

What is claimed is:

l. In a multi-push rod mechanism of the type having a plurality of spaced laterally oiset push rods and latch bar mechanism including a latch bar whereby a push rod when moved from a normally biased out position to in position will move said latch bar to unlock any previously locked push rods and lock said last operated push rod to an in position, the improvement which conown latch bar tooth, each push rod and latch bar tooth cooperating so that when a push rod is moved inwardly the latch bar is first moved longitudinally from a normal locking position to a temporary unlocking position and then moved back to its normal locking position whereby said latch bar will lock apush rod to an in position and will unlock any previously locked push rods, an additional push rod normally biased to an out position and movable through an intermediate in position to an extreme innermost position, spring biased means operatively connecting said latch bar and said additional push rod only when said additional push rod moves from its out position to its in position for moving said latch bar to an unlocking position, and means for locking said additional push rod to an in position after it is rst moved from its out position to its innermost position and then goes out to the in position for unlocking said additional push rod when moved from its locked in position to its innermost position whereby said additional push rod can respond to its bias and return to its normal out position, said spring biased means comprising a dog pivotally secured to said latch bar and having a part movable in a direction generally parallel to the direction of movement of said additional push rod, said dog and additional push rod having cooperating cam surfaces so that said dog will not yield when the latch bar and additional push rod are to be engaged.

References Cited in the iile of this patent UNITED STATES PATENTS Williams Oct. 28, 1958 

